Unisaw kickback prevention

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Forum topic by Hotpuppy posted 12-25-2013 08:34 PM 2294 views 0 times favorited 7 replies Add to Favorites Watch
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69 posts in 1774 days

12-25-2013 08:34 PM

Hey gang, I need some help sorting out the various safety devices. I have a 1950 Delta Unisaw, right tilt. I have a biesemeyer fence and the overhead/arm blade guard. The blade guard has seen better days, but it’s there and mounted. I purchased this saw used and got a good deal on it. I built a dolly for it.

I moved the power switch off the base cabinet and up and out where it is easier to get to.

One major issue is that the saw has no anti-kickback, splitter, or riving knife. I have a healthy amount of respect for cutting tools and I like my fingers… even the little ones. :)

I originally purchased a MJ Micro Jig Splitter. I purchased a GRR-ripper to go with it. I think the gripper looks like a good tool, but the micro-jig splitter seems complicated to set up. I get the impression it’s touchy and was annoyed to find that it requires a separate ZCI for each usage scenario. While it helps with splitting it does not address anti-kickback. I think this will wind up wearing out and being a PITA to setup. I’m also rather unimpressed with the cheap plastic alignment jig. It’s just a matter of time before the drill bit screws up the plastic jig. Granted, it’s a $45 tool.. I would have happily paid more for a better jig. I’m interested in a simple, easy to use solution that helps me stay safe. I’m also annoyed that they appear to have been more interested in keeping the instructions on a single piece of paper then in making them easy to follow.

I have also looked at the board-buddies product (peachtree woodworking) and that product makes sense.

I looked at the BORK, I suspect it would work. It looks over-priced for what it is. The YouTube videos from the manufacturer are very bad, no sound. No anti-kick back pawls…. so it’s essentially a wash with the MJ splitter.

I looked at the shark-guard. This product also make sense and offers to kill multiple birds with one stone. It does not appear to be compatible with the biesemeyer blade guard… which is nice, but the guard itself on the one I have is in poor shape and needs to be replaced. It’s plastic and does what plastic does over time….. cracked and discolored. I was going to put the version on that has a dust port.

I’m looking for feedback on other people’s experience and recommendations…. if you have seen comparison articles that would be great too.

This is a picture of my saw from today…. the blade guard is moved forward so it is not in the way when I go to move it around the shop. It also helps me avoid walking into the blade guard. :)

If I went with the Bork or Shark I would re-purpose the overhead arm to manage a dust collection hose.


7 replies so far

View AlanBienlein's profile


159 posts in 2702 days

#1 posted 12-25-2013 08:42 PM

There was one posted here on lumberjocks. This is the thread.

In that thread there is another link to the actual construction of it.

View AlanBienlein's profile


159 posts in 2702 days

#2 posted 12-25-2013 08:45 PM

And here is another link for one posted here on lumberjocks.

View Hotpuppy's profile


69 posts in 1774 days

#3 posted 12-25-2013 09:05 PM

Both of these are intriguing… but I was hoping to not get into machining a riving knife system. :) I do have access to machine tools and a CNC plasma cutter though… and I can weld.

View unbob's profile


810 posts in 1931 days

#4 posted 12-26-2013 12:09 AM

I know this is a radical suggestion. They actually made a guard system for the saw with splitter and anti kick back pawls, that probably came with the saw when new.
I use that on my similar 12” 7.5 hp Delta.

View Hotpuppy's profile


69 posts in 1774 days

#5 posted 12-26-2013 12:41 AM

I actually had not considered the stock splitter….

It looks like there is a disappearing splitter available and then the biesemeyer ones… the bies ones are $200+

The disappearing one is $140.

Which style do you have on your machine?

View runswithscissors's profile


2768 posts in 2053 days

#6 posted 02-10-2014 02:07 AM

I doubt if pawls will prevent any kickback that is likely to happen with a proper riving knife, since kickback is caused either by the material pivoting into the back of the blade (see U Tube videos demonstrating this), or from the stock closing up and pinching the blade. The riving knife addresses both of these. A splitter can do the same thing, but just not quite as well. Also, the pawls in most guards are made from very light gauge sheet metal, and I suspect would simply crumple under the forces of a really bad kickback, especially with a 3 hp. saw.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View CharlesA's profile


3329 posts in 1826 days

#7 posted 02-10-2014 02:19 AM

I use the MJ splitter pro, and I’m a little confused. You do have to be precise in setting it up, but many have done so successfully. I don’t understand the ZCI issue. I use TK blades, and I use the same ZCI with all my blades with no problem. I use homemade ZCI’s for different width dados, but that would be the case with the MJ splitter or not. Short of a riving knife or one of the far more elaborate solutions, I think the MJ splitter works as well as anything on the market.

-- "Man is the only animal which devours his own, for I can apply no milder term to the general prey of the rich on the poor." ~Thomas Jefferson

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